Washable, sterilisable, reusable masks are no longer manufactured, as disposable masks have been introduced worldwide. This makes it difficult to find the fabrics that were used to manufacture them on the market.
The process of manufacturing reusable masks has various stages. First, textiles must be selected that have a high capacity to filter microparticles. Second, trials must be undertaken to confirm their filtering capacity, transpiration and breathing capacity (in Spain, such tests are only carried out at the AITEX technology centre in Valencia). Then, the fabric must be manufactured and supplied and finally the masks have to be made in such a way that they perfectly fit the face of the healthcare professional.
Healthcare masks must be hydrophobic, particularly on the outside, and must meet the healthcare regulations FFP1, FFP2 or FFP3. Certification takes time although, after amendment of current legislation in Spain on 20 March, this time will be cut. The use of domestic masks is not advisable. In case of extreme need, experts recommend using the most suitable fabrics to manufacture temporary masks that are not for clinical use.
For temporary, non-healthcare use, cotton is totally unadvisable as it absorbs water and micro-drops containing the virus. In addition, it is a fabric that, if it is not treated with antibacterial coatings, promotes the growth of bacteria.
Therefore, the most suitable fabrics for constructing protective masks will be fabrics with little water absorption, made with hydrophobic fibres or those that absorb little water (such as polyester or polypropylene).
In the Official State Gazette (BOE) on 20 March, Provision 3995 of the Ministry of Industry, Trade and Tourism was published on alternative exceptional specifications for the manufacture of personal protection masks, due to the lack of this material and while the state of exception lasts. According to this provision, healthcare masks that meet NIOSH and Chinese standards can be marketed in Spain, with the validation of health authorities in the autonomous communities and if they have technical documents that guarantee the following three specifications: efficacy against penetration, resistance to breathing and labelling.